Recent advances in evoked potential brain response techniques have shown this method to be capable of predicting language skills with a high degree of accuracy. In one study, factor scores based on AERs recorded at birth were used as independent variables in regression models to predict language scores obtained from the subject at age 3 years. Seventy-eight percent and sixty-nine percent of the total variance were accounted for in predicting language scores on the McCarthy Scales of Children's Abilities and the Peabody Picture Vocabulary Test, respectively. This research proposal outlines procedures for assessing the reliability and validity of these findings with a larger subject population. The subjects will be normal infants and infants "at risk" for abnormalities in development due to prematurity, poor postnatal status and perinatal risk factors. Infants selected as subjects will be those whose parents consent to (1) permit medical records information to be opened (for birthweight, gestational age, Apgar and obstetric complications information), (2) allow behavioral (Bayley, McCarthy and Peabody Scales) and electrophysiological (AERs to synthetic CV syllables) testing and (3) who are willing to participate for the three year duration of the project. The results of this study will permit us to determine if the original predictors continue their high levels of accuracy in identifying later language skills and to determine the extent to which electrophysiological measures obtained from more heterogeneous subjects allow for early discriminations to be made concerning later language performance. The contribution of AER measures (factor scores, amplitude measures, and template correlations) will be compared with measures of perinatal risk, socioeconomic status, home environment, mother-infant interactions, developmental assessment scores to determine the relative contribution of these variables to the prediction of language performance measures.